1. Technical Field
The present disclosure relates to the field of signal conditioning in high-speed wireline communications. More specifically, the present disclosure relates to systems and methods for peak detection in automatic gain control circuits such as may be used in adaptive equalization control in high-speed wireline communications.
2. Discussion of Related Art
Whenever electrical signals are transmitted over wires, the integrity of the signals can be degraded. Thus, the signal that was originally placed on the wire will have some differences from the signal that is received at the other end of the wire. This is due to inherent physical properties of the wire.
In a digital signal, the frequency components of a bit can get spread apart as the higher and lower frequency components travel at slightly different rates through the wireline, causing intersymbol interference (ISI). In recent years, as data has been required to travel at faster speeds and over longer wirelines, the problems of maintaining signal integrity and minimizing ISI have increased.
Several techniques have been developed to deal with ISI, including adaptive equalization, which have been found to have some advantages. Adaptive equalizers self-adjust to tailor the response to best counteract the effects of the wireline on a signal. Some adaptive equalizers incorporate peak detection circuits, which monitor and provide the peak signal levels of the incoming signal. However, many peak detection circuits have significant drawbacks. Closed-loop peak detection circuits can consume excessive amounts of power, and open-loop peak detection circuits can also suffer limitations due to finite transconductance in sub-micron CMOS processes. What is needed are improved peak detection methods and circuits.